The purpose of this project is to facilitate the development of adjunct hyperthermia modalities for cancer treatment by theoretically and experimentally studying the spatial and temporal variation in the temperature field of tissues subjected to microwave and radio-frequency electromagnetic radiation. currently, we are (1) experimentally measuring the patterns of energy deposition within various types of extremity phantoms produced by a Mini-Annular Phased Array (MAPA) applicator; (2) theoreticallly describing the electromagnetic fields of a MAPA in terms of its design paramters; (3) theoretically describing the transient thermal profiles within limbs produced by a MAPA; and (4) theoretically describing the systemic temperature and cardiac changes associated with heating various regions of the body. We are also performing electromagnetic and thermal modeling of the unwanted non-local energy deposition occuring outside the bounds of typical hyperthermia applicaotrs. These studies are forming the basis for the clinical system currently under construction.